Controlling apparatus for highway crossing signals



April 19, 1938. G. R. PFLASTERER ,1 4,90

CONTROLLING APPARATUS FOR HIGHWAY CROSSINQ SIGNALS Filed July 18, 1936 k-Li INVENTOR 26 Q George flastere HIS ATTORNEY Patented Apr. 19, 1938 til AT S ATENTI oFFcE CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Application July 18,

6 Claims.

My invention relates to controlling apparatus for highway crossing signals, that is, to apparatus for the control of signals which are placed at intersections of railways and highways for the purpose of warning users of the highway when a train is approaching.

I will describe five forms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

Fig. 1 of the accompanying drawing is a diagrammatic view illustrating one form of apparatus embodying my invention as applied to a stretch of track over which traffic moves in both directions. Figs. 2,3, 4., and 5 are diagramlfi matic views each illustrating a modification of a portion of the apparatus shown in Fig. 1 and each also embodying my invention.

Similar reference characters refer tosimilar parts in each of the several views.

Referring first to Fig. 1, the reference characters! and Z designate the rails of a stretch of track over which traffic moves in both directions. The stretch is divided by insulated joints 3 into two adjacent sections designated by the reference gtcharacters IT and ET, respectively. Each track section is provided with a track battery lconnected across the rails at one end of the section and with a track relay, designated by the reference character R with aprefix the same as the 5 ;.reference character of the associated section, con: nected across the rails at the other end of the section. As here shown, the relays iTR and 2TB are the magnets of an interlocking relay K; Located adjacent the junction of sections IT and 2T 5;;is anintersection of the. rails of the stretch and a highway 1-1. The highway H is protected by a signal S of any suitable type. As here shown, the signal S includes a green lamp G for displaying a proceed indication, a yellow lamp Y for, dis- 40 playing a caution indication, and a red lamp R for displaying a stop indication. The signal S is controlled jointly by relay K and a relay XP having a slow releasing characteristic. The relay XP is controlled by the interlocking relay K.

With both sections IT and 2T unoccupied so that both magnets lTR and 2TB are energized, the relay XP is supplied with energy to cause such relay to assume its initial condition and, consequently, the green lamp G is energized. The -.circuit for relay XP may be traced from terminal B ofany suitable source of energy over front flagman contact 6 of magnet lTR, front flagman contact 1 of magnet 2TB, and relay XP to terminal C of the same source of energy." 55 The circuit for the green lamp G may be traced 1936, Serial No. 91,419

from terminalB through front fiagman contact 6-of magnet iTR, front fiagman contact I of magnet 2TR, frontpointof contact 8 of relay XP, and lamp G to terminal 0.

I shall now assume'that an eastbound train, that'is, a train moving from left to right, enters section IT so that magnet ITR becomes released. When magnet ITR is released, relay 2Q will become deenergized and back contact 9 of magnet iTR. will become closed. A circuit will then be completed for the yellow lamp Y to cause the signal to display the caution indication. The circuit for lamp Y may be traced from terminal B over back contact 9 of magnet ITR, front point of contact I!) of relay XP, and lamp Y to terminal C. At the expiration of a given time interval, when relay XP attains its operated condition, a circuit will be completed for the red lamp R to cause the signal to display a stop indication. This circuit may be traced from terminal B over back contact 9' of magnet ITR, back point of contact ll! of relay XP, and lamp R to terminal'C. When the train vacates section IT and enters section 2T, magnet iTR will become energized and magnet 2TB will become deenergized. Because the relay K, however, is of the interlocking type, front"fiagman contact I of magnet 2TB. will not become opened and back contact I I of magnet 211% will not become closed. Relay XP, therefore, will again assume its initial condition so that green lamp G will be energized over the previously traced circuit for this lamp. When the traindeparts from section 2T, the magnet Z'IR will again become energized to restore all apparatus to its normal condition.

It will be understood that the release time of relay 2G? is such that the caution signal will be displayed for a length of time sufficient to give users of the highway ample warning before the display of'the stop signal.

While I have described the operation of the apparatus shown in Fig. 1 for an eastbound train only, it will be readily apparent how the apparatus operates for a train moving in the opposite direction.

It will be noted that the caution lamp Y is providedwith another circuit including the back point'of contact 8 ofrelay XP. This circuit insures that the caution lamp will be lighted, when contacts 6-. and l of relay K become closed, in the event that relay XP should fail to assume its initialcondition to light the proceed lamp.

Referring next to Fig. 2, the reference char-. acter XPA designates a relay having a slow release characteristic which relay is controlled by a front contact i2 of the relay XP. That is, relay XPA will assume its initial condition when relay XP is in its initial condition, and will assume its operated condition a predetermined time interval after relay XP attains its operated condition. This arrangement is sometimes useful when it is desirable to display the caution signal for a period of time greater than can be obtained by the release time of relay XP alone. The lamps G, Y, and R are controlled by the relay K and relay XPA in a manner similar to that described for the apparatus shown in Fig. 1. That is, the green lamp circuit includes front flagman contacts 6 and 'l of magnets [TR and ZTR, respectively, and front point of contact l3 of relay XPA; the caution lamp circuits include either back contact 9 of magnet ITR or back contact II of magnet 2TR and front point of contact M of relay XPA; and the red lamp circuits include either back contact 9 of magnet ETR or back contact ll of magnet 2TR and back point of contact M of relay XPA. The yellow lamp Y is also provided with an auxiliary circuit, including the back point of contact l3 of relay XPA, for lighting that lamp in the event that relay XPA fails to assume its initial condition when contacts 6 and 'l of relay K are both closed.

Referring next to Fig. 3, the reference character TE designates a timing device here shown as a thermal relay. The relay TE is controlled by contacts 6 and l of relay K in the same manner as relay XP. That is, relay TE will assume its initial condition when energized by the closing of both front contacts 6 and l and will assume its operated condition a predetermined time interval after becoming deenergized by the opening of either contact 6 or contact 'I. The green lamp G is provided with a circuit which includes both contacts 6 and i so that the lamp G will become lighted whenever both magnets lTR and ZTR are picked up regardless of the condition of relay TE. The yellow lamp is provided with circuits which include either back contact 9 or back contact H of relay K and front contact l5 of relay TE. The red lamp R is provided with circuits which include either back contact 9 or back contact H of relay K and back contact it of relay TE. Contacts l5 and It will be so adjusted that contact it will become closed only when relay TE is in its operated condition and contact :5 will become closed when relay TE is in its initial condition and will remain closed until just before contact |6 becomes closed. The signal S, therefore, will display the proceed indication when both contacts 6 and l are closed and will display either the caution indication or the stop indication, when either back contact 9 or back contact ll of relay K becomes closed, depending upon whether contact 15 or contact it of relay TE is closed.

Referring now to Fig. 4, the reference character J designates a relay provided with a pickup magnet Mi of comparatively low resistance and with a holding magnet M2 of comparatively high resistance. The relay J, as here shown, is provided with a dashpot designated by the reference character I! which is operably connected to the relay armature E8 to cause that armature to be slow in releasing. Under normal conditions, that is, with both contacts 6 and 1 of relay K closed, relay J is energized over a holding circuit which passes from terminal B through front contact 6 of magnet ITR, front contact I of magnet 2TB, magnet M! of relay J, front contact IQ of relay J, and magnet M2 of relay J to terminal C. When relay J is in its operated condition, a pickup circuit is provided which includes front contacts 6 and l of relay K and back contact 20 of relay J. Contacts I9 and 20 are so adjusted that back contact 20 will not become opened before front contact 19 becomes closed. The pickup circuit for relay J, therefore, is of comparatively low resistance to cause a correspondingly strong attraction of the armature [8, but the holding circuit is of comparatively high resistance so that normally the current consumption of relay J is small. Relay J is provided with a contact 2| which is closed when relay J is in its initial condition and which remains closed until just before the relay attains its operated condition,

and with a contact 22 which is closed only when the relay is in its operated condition. The relay J governs the yellow and green lamps in a manner similar to that just described for relay TE. That is, the yellow lamp is lighted over circuits which include front contact 2| of relay J and the red lamp is lighted over circuits which include back contact 22 of relay J.

Referring next to Fig. 5, the reference character Q designates in general a timing device which controls the yellow and red lamps Y and R in a manner similar to that just described for the relays TE and J in Figs. 3 and 4, respectively.

As here shown diagrammatically, the device Q comprises a motor 23, which when energized, rotates a camshaft, indicated by dotted line 24, in a counter-clockwise direction to wind-up by means of a pinion 25, a coiled spring 26 of a clockwork 21. Rotating with shaft 24 is a contact actuating cam 28. When shaft 24 is rotated counter-clockwise by motor 23 to windup the clockwork mechanism, cam 28 is rotated to the position shown in Fig. 5 when the device is in its initial or wound-up condition. When the wound-up condition is attained, the motor circuit is opened at contact 29-30 and the clockwork mechanism is then held latched in this condition by the energization of holding coil 3|. The apparatus shown in Fig. 5, in so far as the control of contact 2930 is concerned, is similar to contact 19 of United States Letters Patent No. 1,896,120, granted February 7, 1933, to Henry S. Young and Howell N. Dixon. the holding and operating circuits both include front contacts 6 and 'l of relay K and may very readily be traced. When holding coil 3| becomes deenergized, spring 26 will drive cam 28 in a clockwise direction so that at the expiration of a given time interval, contact 32-33 will become opened and contact 3234 will become closed.

The contact 3233 controls the yellow lamp Y and the contact 3234 controls the red lamp R. The green lamp G is controlled in the usual manner by contacts 6 and 1 of relay K. That is, the green lamp G is lighted when both contacts 6 and 'l are closed and the yellow lamp Y or the red lamp R will become lighted, when either magnet ITR or ZTR is released depending upon whether contact 32-33 or contact 3234 is closed.

From the foregoing description of the apparatus embodying my invention, it will be seen that I have provided, at an intersection of a railway and a highway simple and reliable apparatus for displaying a proceed, a caution, and a stop signal in accordance with traffic conditions on the railway.

Although I have herein shown and describedonly a few forms of apparatus embodying 'my invention, it is understood that various changes and modifications may be made therein withinthe scope of the appended claims without departing from the spirit and scope of my invention.

Having .thus described! my invention, what I claim is:

1. In combination, a stretch of railway track including an intersection with a highway, a track section included in said stretch so located as to become occupied by a train approaching said intersection, a track circuit including a track relay for said track section, a device capable of assuming an initial condition when energized and an operated condition a predetermined interval of time after becoming deenergized, means including a front contact of said track relay effective to energize or deenergize said device according as said track relay is picked up or released respectively, a signal located at said intersection, means effective to cause said signal to indicate proceed when said track relay is picked up provided said device is then in its initial condition, means effective to cause said signal to indicate caution or stop when said track relay is released according as said device is then in its initial condition or its operated condition respectively, and means also effective to cause said signal to indicate caution if said device remains in its operated condition when said track relay is picked up.

2. In combination, a stretch of railway track including an intersection with a highway, a track section included in said stretch so located as to become occupied by a train approaching said intersection, a track circuit including a track relay for said track section, a device capable of assuming an initial condition when energized and an operated condition a predetermined interval of time after becoming deenergized, means including a front contact of said track relay effective to energize or deenergize said device according as said track relay is picked up or released respectively, a signal located at said intersection and including a proceed lamp as well as a caution lamp and a stop lamp, a circuit for said proceed lamp including a front contact of said track relay and a contact which is closed when said device is in its initial condition, a circuit for said caution lamp including a back contact of said track relay and a contact which is closed when said device is in its initial condition, another circuit for said caution lamp including a front contact of said track relay and a contact which is closed when said device is in its operated condition, and a circuit for said stop lamp inc1uding a back contact of said track relay and a contact which is closed only when said device is in its operated condition.

3. In combination, a stretch of railway track including an intersection with a highway, a track section included in said stretch so located as to become occupied by a train approaching said intersection, a track circuit including a track relay for said track section, a signal at said intersection including a proceed indication unit as well as a caution indication unit and a stop indication unit, a slow releasing auxiliary relay which is energized or deenergized according as said track relay is picked up or released respectively, a circuit for said proceed indication unit including a front contact of said track relay and a front contact of said auxiliary relay,'a circuit for said caution indication unit including a back contact of s'aid'track relay and. a. front contact ofisaid. auxiliary'relay', another circuit for said cautionindication unit including afront contact OfzSfild'ltIZtCkl'ElQJ and a back contact of said auxiliary-relay, and acircuitfor said stop indication: unit including a back contact of said track relay and a. back contact of said auxiliary relay-..

4. In combination, a stretch of railway track including an intersection with a highway, a track section included in said stretch so located as to become occupied by a train approaching said intersection, a track circuit including a track relay for said track section, a signal at said intersection including a proceed indication unit as well as a caution indication unit and a stop indication unit, a first auxiliary relay governed by said track relay in such a manner as to assume an initial condition when said track relay is icked up and an operated condition a predetermined time interval after said track relay is released,,a second auxiliary relay governed by said first relay in such a manner as to assume an initial condition when said first relay is in its initial condition and an operated condition a predetermined time interval after said first relay attains its operated condition, means for energizing said proceed indication unit when said track relay is picked up provided said second auxiliary relay is then in its initial condition, means for energizing said caution indication unit when said track relay is released provided said second auxiliary relay is then in its initial condition, means also efiective to energize said caution indication unit if said second auxiliary relay remains in its operated condition when said track relay becomes picked up, and means for energizing said stop indication unit when said track relay is released provided said second auxiliary relay is then in its operated condition.

5. In combination, a stretch of railway track including an intersection with a highway as well as a first track section so located as to become occupied by a train approaching said intersec tion from one direction and a second track section so located as to become occupied by a train approaching said intersection from the other direction, an interlocking relay including a first magnet which is energized only if said first section is unoccupied and a second magnet which is energized only if said second section is unoccupied, a timing device capable of assuming an initial condition when energized and an operated condition a predetermined time interval after becoming deenergized, means effective to energize said timing device provided both said magnets are picked up, a signal located at said intersection and including a proceed lamp as well as a caution and a stop lamp, means effective to energize said proceed lamp provided said timing device is in its initial condition when both said magnets are picked up, means effective to energize said caution lamp provided said timing device is in its initial condition when either magnet is released, means also effective to energize said caution lamp if said timing device remains in its operated condition when both said magnets are picked up, and means effective to energize said stop lamp provided said timing device is in its operated condition when either magnet is released.

6. In combination, a section of railway track including an intersection with a highway, a track circuit including a track relay for said section, a

slow release relay, a circuit for said slow release relay including a front contact of said track relay, a three-indication signal at said intersection, a proceed circuit for said signal including a front contact of said track relay and a front contact of said slow release relay, a caution circuit for said signal including a front contact of said track relay and a back contact of said slow release relay, another caution circuit for said signal including a back contact of said track relay and a front contact of said slow release relay, and a stop circuit for said signal including a back contact of said track relay and a back contact of said slow release relay.

GEORGE R. PFLAS'I'ERER. 

